The present invention relates to a system that provides navigation-related services and data to end users throughout a geographic region, and more particularly, the present invention relates to a system that includes a centrally-located server that has a geographic database associated therewith and that provides navigation-related services and data to end users"" computing platforms that are located throughout a serviced geographic region.
Navigation systems provide various useful features, such as calculating routes to desired destinations, providing guidance for following calculated routes, displaying maps, and so on. There are various computer architectures for navigation systems that deliver navigation-related and map-related features. In one type of architecture for a navigation system, end users (such as vehicle drivers) have local navigation system units. These end users"" local navigation system units obtain geographic data from a remotely-located geographic database. The remotely-located geographic database contains a relatively large amount of geographic data. A server associated with the remotely-located geographic database handles requests for navigation-related or map-related data from end users"" local navigation system units. When an end user""s local navigation system unit requests data, the server accesses the geographic database associated therewith to obtain the necessary data to respond to the request and then sends the data to the requesting end user""s local navigation system unit.
This type of navigation system architecture provides several advantages. One advantage relates to providing updated geographic data. There is a continuing need to update the geographic data used by a navigation system. For example, new streets are built, road construction closes roads, detours are established, new businesses open, posted speed limits change, new turn restrictions are established at intersections, streets are renamed, and so on. These kinds of changes can affect travel through a geographic region. Accordingly, the geographic data used by a navigation system should be updated on a regular basis in order to accurately reflect changes in the represented geographic features. A computer architecture in which individual local navigation system units obtain geographic data from a single geographic database affords an advantage with respect to the updating of the geographic data. With a computer architecture in which individual local navigation system units obtain data from a single geographic database associated with a central server, updates need to be applied only to the central database.
Although there are advantages associated with a navigation system architecture in which individual navigation system units obtain data from a single geographic database associated with a central server, there are considerations that need to be addressed. One consideration relates to providing data for a variety of different computer platforms used by end users. It is preferable that the central server support various different types of end user computer platforms. These different end user computer platforms may have different resources, such as different amounts of memory, different processor speeds, different operating systems, etc. Some of these different types of end user computer platforms may include general purpose computing devices that run navigation applications. Other end user computer platforms may include dedicated devices, such as in-vehicle navigation systems. Some of these different end user computer platforms may provide both audio and visual information to an end user, whereas other end user computer platforms provide only audio or only video. It would be preferable that each computer platform receive geographic data that are appropriate for the resources of the platform. This includes sending sufficient data in order to utilize the available resources of the computing platform in a meaningful way, but not sending data that cannot be used on the platform.
Thus, there is a need for an improvement that allows a server that provides navigation-related services and data to support different kinds of end user computing platforms.
Further, in a navigation system architecture in which data are transmitted from a central server to end users"" computing platforms, there is a need for an improvement that allows data to be managed efficiently on both the server and on the end users"" computing platforms.
To address these and other objectives, the present invention comprises a system and method for providing navigation-related services to end users"" computing platforms. A server maintains downloadable geographic data that are organized into pre-computed parcels that correspond to pre-determined sub-areas into which the entire geographic region serviced by the server is divided. The server responds to requests for navigation services and data by sending selected pre-computed parcels of geographic data to end users"" computing platforms. Each of the end users"" computing platforms stores the parcels received from the server in a memory cache. The end users"" computing platforms use the data in the parcels to provide navigation-related features locally.